Synthesis and solution properties of cylinder brushes derivated by internal domain locking of poly(diblock macromonomer)s

摘要

Poly(diblock macromonomer)s (diblockcopolymer brush) were synthesized by free-radical homopolymerizations of vinylbenzyl-terminated poly(#alpha#-methylstyrene)-block-poly(2-vinylpyridine) (PMS-block-P2VP) diblock macrori1onomer. Dilute-solution properties of such diblock copolymer brushes were investigated by static (SLS) and dynamic light scatterings (DLS) and small-angle X-ray scattering (SAXS). Effective diffusion coefficient Dell" for polymer brushes with various aspect ratios showed the almost constant value in the range of polymer concentration 0-5 x 10~(-3) g/cm:l. These results indicated that polymer brushes formed unimolecule structure even in good solvent such as benzene. It was speculated from angular dependence measurements that polymer brushes with large aspect ratios took geometrical anisotropic conformation such as cylinder. Subsequently, the cylinder brushes were derivated by crosslinking of internal P2VP domains of diblock copolymer brushes with 1,4-diiodobutane. These cylinder brushes also formed unimolecular structure in a dilute solution. However, sernidilute solution properties of cylinder brush show a clear.plateau region,which originates from entanglement effect. This entanglement is Icaused by the thlD thickness of PMS shell.